eGFR slope improvement with SGLT2 inhibitors is not statistically associated with changes in urinary protein in Japanese CKD patients: a single-center real-world analysis

Abstract Background SGLT2 inhibitors reduce urinary protein and slow eGFR decline in clinical trials. However, real-world evidence on within-patient changes in eGFR slope before and after treatment initiation, and their relationship to changes in urinary protein, remains limited. This study was designed to address these concerns. Methods This retrospective study included 90 Japanese CKD patients who initiated dapagliflozin and had ≥ 5 eGFR measurements during both the 12-month periods before and after initiation. The treatment effect was defined as the ΔeGFR slope (post-minus pre-initiation slope). Clinical factors associated with ΔeGFR slope were assessed using multivariable regression. Results The mean eGFR slope significantly improved from − 5.12 ± 5.93 to 1.59 ± 5.27 mL/min/1.73 m 2 /year ( p < 0.0001). Urinary protein decreased modestly without statistical significance (median 0.65 − 0.55 g/gCr, p = 0.155). Significant improvements in eGFR slope were observed regardless of baseline urinary protein level or the reduction rate. Multivariable analysis revealed that a reduction in serum uric acid ( β = − 0.26, p < 0.001), but not urinary protein, was independently associated with the ΔeGFR slope. Conclusions Dapagliflozin significantly improves the eGFR slope, which was not statistically associated with urinary protein changes in this cohort, in routine clinical practice. These findings underscore the clinical value of eGFR slope-based evaluation for monitoring individualized therapeutic responses.